driver: net: ti: cpsw: update to use SPDX identifier

Update to use SPDX license identifier.

Reviewed-by: Tom Rini <trini@konsulko.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
diff --git a/drivers/net/ti/cpsw.c b/drivers/net/ti/cpsw.c
index 8e2a48c..fe43d14 100644
--- a/drivers/net/ti/cpsw.c
+++ b/drivers/net/ti/cpsw.c
@@ -1,16 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0+
 /*
  * CPSW Ethernet Switch Driver
  *
- * Copyright (C) 2010 Texas Instruments Incorporated - http://www.ti.com/
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation version 2.
- *
- * This program is distributed "as is" WITHOUT ANY WARRANTY of any
- * kind, whether express or implied; without even the implied warranty
- * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
+ * Copyright (C) 2010-2018 Texas Instruments Incorporated - http://www.ti.com/
  */
 
 #include <common.h>